Numerical Study of Single Phase/Two-Phase Models for Nanofluid Forced Convection and Pressure Drop in a Turbulence Pipe Flow

Abstract

In this paper, the problem of turbulent forced convection flow of water- alumina nanofluid in a uniformly heated pipe has been thoroughly investigated. In numerical study, single and two-phase models have been used. In single-phase modeling of nanofluid, thermal and flow properties of nanofluid have been considered to be dependent on temperature and volume fraction. Effects of volume fraction and Reynolds number (3000<Re<9000) on convective heat transfer coefficient and pressure drop were investigated for various axial locations of the tube. Numerical results have shown that the inclusion of nanoparticles into the base fluid produced a considerable augmentation of the heat transfer coefficient that increases with an increase of the volume fraction and Reynolds number. Moreover, the increase of volume fraction has no effects on the coefficient of friction, but it decreases with increasing Reynolds number. Comparison of numerical results with experiments shows that the results of single- phase analysis is near to the experimental results.